Thursday, November 27, 2008

World's Oldest Person Dies

Edna Staples, the oldest person in the world, has recently passed away. She was 115 years and 220 days old. Parker was born April 20, 1893, in central Indiana's Morgan County.

Parker taught in a two-room school in Shelby County for several years after graduating from Franklin College in 1911. She wed her childhood sweetheart and neighbour in 1913. Two years ago she was named as the oldest living person by Guinness Book of World Records. She never drank alcohol or tried tobacco, and led a very active lifestyle, but when asked about tips to longevity, her only advice was "more education".

Now the oldest person is Maria de Jesus of Portugal, born September 10, 1893, who is currently 115 years, 78 days old.

Tuesday, November 25, 2008

An Eye Opening Genetic Malformation

During the development of an embryo there are many critical processes simultaneously at work , including body axis specification and formation of functional organs. Another important element is the development of the head, arguably the most anatomically sophisticated region of the body. On rare occasions craniofacial malformations will occur, resulting in disorders that have many potential origins, including abnormalities of brain patterning, of the migration and fusion of tissues in the face, and of bone differentiation in the skull.

Holoprosencephaly (HPE) refers to a range of problems involving the malformation of the brain and upper face along the midline. In the most moderate of circumstances, the signs of HPE are as subtle as one single central incisor, shown above on the left. The most extreme end of the spectrum can be associated with midline cleft lip, cyclopia, and an overlying proboscis, shown above on the right. The proboscis, which is the build-up of tissue seen above the eyes, forms because of the obstruction by the central eye. It is made up of frontonasal neural-crest cells that would have normally migrated between the eyes to form the nose and upper lip.

This is extremely rare in live births (~1 in 15,000), but is more commonly detected in early pregnancies (1 in 250); however almost all affected fetuses are miscarried. The cause of these deformities is thought to be due to mutations in the SHH gene. Source of pictures and information: Wilkie et. al (2001) Genetics of Cranofacial Development and Malformation, Nature Reviews Genetics, Volume 2; 458-468.

Friday, November 21, 2008

RIP Debby

Sadly, Debby died a few days ago in her home at the Winnipeg Zoo where she lived to the beyond-ripe age just shy of 42. This was not surprising news, as her health had been deteriorating quickly over the past few months. See the post made on August 1st.

She was recognized in the 2008 Guiness Book of World Records as the oldest polar bear.

Thursday, November 20, 2008

Pocket Primate

The pygmy tarsier (tarsius pumilus) last spotted in 1920, was thought to be extinct, until recently when a team of researchers captured three (two males + one female) in an Indonesian cloud forest on Mount Rore Katimo in Lore-Lindu National Park. They attached radio collars to their necks in order to track their movements and released them.

These little nocturnal creatures weigh less than 60 grams and have dense fur that keeps them warm in their cold habitat at high altitudes. Its eyes cannot move, so when hunting for small insects or vertebrates it turns its head 180 degrees. Unlike other primates it has claws, rather than nails.

Thursday, November 6, 2008

Cloning The Frozen

A team of Japanese geneticists used cells from a dead mouse frozen for 16 years and successfully created healthy clones. They took dead brain and blood cells from the frozen mice, and injected the nuclei from them directly into unfertilized mouse eggs. By extracted inner cell mass from each embryo, they generated embryonic stem cells. Eventually they were able to produce 13 mouse pups. The nuclei from these cells were then transferred into mouse eggs, resulting in the production of healthy pups.

"But in dead cells the cell membrane is broken and the fusion method cannot be used for cloning. In our method, it does not matter whether the donor cells are alive or dead," Wakayama explained.

The technique could eventually lead to the resurrection of extinct animals such as the woolly mammoth, scientists stated in November 2008.